﻿Xlvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



our guard against hastily assuming even the scarcity of this great 

 class in what has been termed the Age of Reptiles. 



If we consult Prof. Owen's work on British Fossil Mammalia and 

 Birds, we find 229 figures devoted to the illustration of the mammalia, 

 and only seven figures to the birds. Three species only had been 

 obtained in 1846 from the English eocene beds, although nineteen 

 British mammalia were known when that treatise appeared. Cuvier's 

 investigations had long before made known to us, that in the eocene 

 gypsum of Montmartre there were ornitholites of the families Acci- 

 pitres, Gallinaceee, Grallatores, and Palmipedes, and it is therefore 

 remarkable that the freshwater deposits of the Isle of Wight and 

 Hordwell Cliff, which had yielded freshwater shells in abundance 

 for half a century, had afforded us no insight into the state of the 

 contemporaneous feathered creation. 



The next point in the palaeontology of the vertebrata of the 

 secondary formations, relates to the fossil mammalia of the slate of 

 Stonesfield. The manner in which the lower jaws of extinct quadru- 

 peds of no less than three species are imbedded in an oolitic matrix, 

 prevents the possibility of any cavil as to the locality from whence 

 they were all derived, and the rock itself is well ascertained to belong 

 to the lowest division of the oolitic system of England. In their 

 state of preservation they rival the beautiful fossils of the Paris 

 gypsum, or those of corresponding eocene date recently obtained from 

 Hordwell Cliff. After the animated discussions which have taken 

 place in this room, it would be a waste of time to repeat to you the 

 arguments by which the Hunterian Professor proved that jaw-bones, 

 consisting of a single piece with double-fanged teeth and convex 

 condyles exhibiting well-developed coronoid processes, cannot have 

 belonged to fish or reptiles. I shall merely allude to the late dis- 

 covery of a more perfect jaw, which enabled Professor Owen's ana- 

 tomical skill to decide that the angular process of the Amphitherium 

 Prevostii was bent inward in a slighter degree than in any of the 

 known marsupialia. The fact of the inflection not exceeding that 

 observable in the jaw of the living mole or the hedgehog, turns the 

 scale in favour of the affinities of the Amphitherium to the placental 

 insectivora, although it still approximates in some points of its osteo- 

 logy to the Myrmecobius and other marsupials of Australia. 



But the precious relic of another mammiferous genus discovered 



